Quang Muku was apparently once home to an ancient civilization, but this was long-fallen by the 14th century DR, remembered only in local myths of a lost city and men who stood 8 feet (2.4 meters) tall. The ancient people lived on as forest-dwelling tribes, known to the Koryoans as savages and strange cannibals.[2]

Two powerful spirits known as the Cosalla Huin To watched over the northern glades of the Quang Muku, making mischief on ordinary travelers and inflicting punishments on those who invaded or harmed the woods.[4]

Many more potent herbs were to be found within the dark recesses of the forest,[2] and they could be distilled into intoxicating potions and other substances. Many of these were known to Bosturo, an expert on the plants of Quang Muku.

A love potion could be brewed from a certain berry found in the Quang Muku Forest. Notoriously effective, it had been used to deceive lovers and bring down strong and influential noble houses. Under its effects, Queen Ki Hiar of Saishu fell in love with a pirate from Wa, and Prince Du-yang of Silla was slain by the jealous husband of a plotting woman.[2]

In the mid–14th century DR, two men and their dog emerged from the Quangu Muku Forest with stories of finding a lost city in the woods, and the gold and gems to match. With these, they swiftly assembled a fresh expedition and set off. In 1357 DR, after being gone six months, they weren't expected to return.[4]